Electric-lighting system and means therefor



June 10, 1924.

W. BROOKE ELECTRIC LIGHTING SYSTEM AND MEANS THEREFOR Filed Amil 1'7. 1923 3 Sheets-Sheet l June 10 1924. 1,496,869

' w. BROOKE ELECTRIC LIGHTING SYSTEM AND MEANS THEREFOR Filed April 17. 1923 3 Sheets-Sheet 2 June 10 1924. 1,496,869

W. BROOKE ELECTRIC LIGHTING SYSTEM AND MEANS THEREFOR Filed April 17. 1923 3 Sheets-Sheet. 3

Patented June 10, 1924.

UNITED STATES WILFRID BROOKE, OF HALE, ENGLAND.

ELECTRIC-LIGHTING SYSTEM AND MEANS THEREFOR.

Application filed April 17, 1923. Serial No. 632,637.

To all whom it may concern:

Be it known that I, WVILFRID BROOKE, a subject of the King of Great Britain and Ireland, residing at Braemar, Laburnum Lane, Hale, in the county of Chester, Eng land, have invented certain new and useful Improvements in or Relating to Electric- Lighting Systems and Means Therefor,-of which the following is a specification.

My invention relates to improvements 'in electric lighting systems and the means necessary for carrying the improved system into practical effect.

In particular, the improvements concern enclosed lighting systems suitable to the conditions obtaining in mines, docks, ships, steel-works, warehouses and other places where gas is present or inflammable material is stored or dealt with.

I employ an improved method and means which facilitate easy application of the lights, sectionalizing of the lights, or of extending any .portion or group of lights or circuits comprised in the system, and I also provide for safe and ready detachment or replacement of any light or switch fitting on a circuit without interrupting the main supply or other lighting on the circuit.

In the system accordin to my invention, there is or are employe in a circuit one electric cable split connection box or more, preferably arranged to establish contact with a twin core armoured cable at any point or points in its length without the necessity of cutting the cable conductors in the case of through going cables. This is effected by splitting the connection box or boxes or making same in sections or halves adapted to clamp the cable and house the bared portions.

Broadl y I-employ terminal or connection boxes split in a manner to enable connections to be made with a cable without cutting the cable, the latter only requiring its cores bared in two places and attachedto the terminals and enclosedv by a clamping or screwing together process of the split box elements.

I also use a lamp-holdersection with lamp and plugs which plug into the split terminal or connection box, said lamp-holder section being held to the former by screwed or other locking devices, the jointing or joint making portions'of the two being machined and socketing together thus rendering the connection substantially flame proof.

For the connection of and establishment of an auxiliary circuit with the primary cable I use a plug switch box structure which can be combined with the split terminal or connection box or which may take the place of the detachable lampholder structure removed from a split terminal or connection box. I may employ any suitable switch such as a double pole double fused plug switch and this may be constructed to prevent plugging in or withdrawal when the switch is in the on position. The switch may be such as to make the circuit quickly,say by a movement of the operating part through 90.

The attached drawings adequately illustrate my improved system and the means necessary to carry same into practical effect.

In the said drawings Fig. 1 is a front elevation, one half in section, showing the split terminal or connection box, the main cable glands, contact devices, the lamp and the support for the lamp casing, etc.

Fig. 2 shows a plan view of the split connection box, the swing fastening bolts, etc.

Fig. 3 is a detail view of a swing fastening bolt device for securing the detachable lamp holder or other fitting to the lower half of the split connection box.

Fig. 3 shows a key for turning the nut on the swing bolt.

Fig. 4 is a plan view showing the insulation disc with cable clamps and the sockets for the plugs which are fixed in the detachable lamp supporting casing.

Fig. 5 is a plan view of the lamp supporting detachable casing, the swing fastening bolts. The view shows the lamp plugs, fuse, &c.

Fig. 6 is a detail end view of one of the cable glands which may be examined with Fig. 1.

Fig. 6 is a 'detail view.

Fig. 7 shows anelevation of a split connection box for the main cable with a socket ing detachable box fixed thereto having a switch and" provision for the leading away of an attached or connected cable to establish an auxiliary circuit for lamps, etc.

Fig. 8 is a sectional elevation of Fig. 7, the section being taken at right-angles.

Fig. 9 is a plan view of the insulated disc which is fitted in the detachable box strucposition.

Fig. 11 is a plan view showing the switch operating handle and the removable bottom cover for the socketing box of the switch.

Fig. 12 shows in separate detail elevation the main element of the rotatable switch in the on position.

Fig. 13 is a diagram illustrating a main cable with split connection boxes, etc., applied according to my invention, as also spht connection boxes with switches and auxiliary cables with lamps of various types,

&c., applied thereto, the diagram indicating possible schemes.

According to my invention I use a main electric cable such as is marked a in Figs. 1, 2, 6 and 13, and this may be of the insulatedtwin core armoured type, and to this I attach my fittings at any place or places in its length. I am enabled to do this without the necessity of cutting such cable conductor in the case of through going cables. This I accomplish in the case of the attachment of a lamp, by making the connection box in halves or sections as for example an upper half I) and a lower half 0, the two halves being secured together by studs 0' engaging registering lugs or cars on the halves. To the upper half I) the'insulating disc cl is removably fixed as by the use of screws cl. This insulating disc has a distance piece d (which serves to separate the bared cores of the cable) and cable clamps d with detachable caps fixed by screws. 1

In efiecting a connection with the main cable, the same in denuded of its armouring for a few inches and the twin wires of the cables are bared and fixed by the cable clamps d d The main cable (it passes through the split coned extension sleeve 71 0 in the box halves b, c and upon said split coned extension sleeves fit the internally coned glands e, which are shown as formed in two parts with bored ears 6, the bored ears fitting screwed spindles e a cast in the box halves b, c and being held in place by nuts 0. Provision is made for earthing the case of the cable connection -box to the cable armouring in any approved or convenient manner. In the construction illustrated the armouring wire of the cable is intended to be clamped between the outer surface of the coned extension sleeves b 0 and the inner coned bore of the cable glands e (see Fig. 6 c

In the insulating disc (1 are fixed metallic contact sockets a? see Figs. 1 and 4.

The lower half of the split connecting box 0 has a flange 0 and is accurately bored and machined, or otherwise contrived, to ensure substantially 'a'gas and water-tight connection with a combined fitting and to obviate any danger from sparking. The connection boxes may'in all cases be filled with bituminous or other insulating material on assembly if desired.

To co-operate with the split cable connection box, is provided the lighting or other combined fittings, each consisting of a socketing element such as the combining lamp support f which has 9. turned or machined spigot f and flange f and which sockets to the split box element a, as Fig. 1 clearly shows.

The-attachment is made by swing bolts, or in other fashion, the drawing showing swing bolts 9 fulcrumed on a pin g held in jaws g, the swing bolts carrying arecessed cylindrical cup 9 with tooth gflthe nut 9 being housed in the recess and the tooth g en a in the slot 9 in the slotted ln "9 wli en th nut g is screwed down. With the nut g being recessed in the cylindrical cup g, a special type of box-key (such as that marked in Fig. 3 is necessary for manipulating the nuts 9 The socketing element f which is locked to the split connecting box 0, as indicated, has a partition 7" which supports the connecting plugs f, f which are pressed into and enga e the sockets d d, the current passing through plug f through the fuse f and wire f to the lamp holder f sup-' portedby the partition f and back through the wire 7' and the plug f An incandescent lamp 7 is shown applied to the lamp holder f and this lamp is enclosed by a glass of any kind, as for example the glass such A. metal guard is also preferably fitted and this may be a as m shown in Fig. 1.

guard m which is east along with a gallery. m for the glass m and a flange m which is fitted to the socketing element f by screws m or other simple means.

It will be noted that the machined spigot is of ample length to slide closely into or to the body portion of the split connection box element a and such spigot is preferably of circular shape. One object is to ensure the breaking of current in a confined space should the enclosed lantern be removed whilst the lamp is burning. A further im portant object is that whilst removing a lantern its case or box (by reason of the machined spigot f) maintains a metallic connection with the earthed split connection b 1 x until after current is broken on the p u tenc ant from shock it there should happen to be a leak on the fitting which is being withdrawn and this guarding is a matter 0 consequence.

Ill

contacts thereby protecting the atrovision for safe- If an auxiliary cable is to be attached in place of a lamp fitting, I use the same split connection box made in parts and which is connected to the main cable by bearing the cable and without cutting the same. This is a split connecting box identical with that already described and made in two halves b c and having the two cores of the. cable connected as described.

The connection for the auxiliary cable is made in a built-up box which is interchangeable for the built-up lantern supporting element f. This built-up box is, as a. whole, marked h and fashioned with a long spigot h accurately machined and which sockets in the box half I). It has a flange 7%, swing bolts 9 and locking recessed cups (7 and projections and nuts 9 which lock the built-up box h to the half 6 as is clearly shown in Figs. 7 and 8.

In this built-up box is fixed an insulating disc 2', which may be built-up, the same having two plugs i, i and two fuses i The plugs 71, i are pressed into and engage the connecting sockets d, (P in the insulating disc (Z thus connecting the said plugs up to the main cable a.

The built-up switch box It has an auxiliary cable receiving sleeve h with tapered or conical exterior and a gland box formed in two parts 72 h having bored ears which fit screwed spindles k cast-in the box, the gland elements being held by nuts 72. all as already described with respect to the main cable glands.

The parts marked 2', i are distance pieces of insulating material which prevents the fuses i from being located across any wrong pair of terminals.

i The switch shown, is of the rotary double pole type and makes and breaks the circuit by rotation through 90.

In the construction shown the spindle of the switch is marked j and has a shaped cross-head j. which engages an undercut socket j attached to the insulating disc at the purpose of this shaped cross-head being to prevent detachment of the switch unless in the ofi position.

The cross-head is shown in the off position in full lines Fig. 9, and, it will be appreciated'that said cross-head and spindle can only be withdrawn when in the off position because when in the on position the cross-head is locked in the socket f as shown by the dotted lines in Fig. 9.

The switch spindle carries an insulated drum in the form of a snail 3' with middisc y" dividing the snail into two parts with four faces or segments to each of the two parts. There are two brass or conducting segments y' i located in the upper part of the snail and m'etallically connected together to form, a through going circuit, the segments being disposed in diametrically opposite positions on two of the four faces of the snail. Similarly two other conducting segments j, j are provided in the lower part of the snail which are metallically connected to form a through going circuit but are located in position 90 from the ones in the other half of the snail, as will be understood from Figs. 10' and 12, and the following description. I also provide two spring contacts k, 7a, 7.2, is for each portion of the drum or snail, as shown most clearly in Fig. 10, these spring contacts being diametrically disposed in pairs, one pair being located 90 in advance of the other pair so as to co-operate with the conducting segments on the snail or drum, whereby the two paths forming the double pole circuit can be completed or broken by a quarter revolution of the spindle y.

In the drawing, Fig. 10, the switch is shown in the off position, but on rotating the snail or drum 90 the current passes through the plug 2" and fuse 2' and down the contact support 7.: through the contact L- and the metallic segments j of the rotatable snail through the cont-act k to the contact support is to which one of the twin cores of the auxiliary cable is held by the pinching screw is. The other core of the auxiliary twin core cable is pinched by the screw 76 to the contact supporting post k and the current passes along contact k to the metallic segments j, 3' of the rotatable switch through the contact Z' the port 71: the fuse i and the plug 2". It will be understood that the auxiliary twin core cable enters the switch box through the sleeve 7L coned on its exterior face and that the armouring is clamped thereon by the cable gland h.

The switch box bottom is enclosed by a cover fixed by screws 70 and said cover 70 has a hole or bearing at is through which the switch spindle j passes. On this cover four ositions are marked, twoon, and two 01?, see Fig. 11.

The switch operating handle is marked 70 and has a boss 70 which is bored right through, as is the end of the spindle, a in in securing the said handle to the spin le. The boss of the operating handle has a pointer 70 which indicates either the on r or off position, and, it will be understood, that in the on position it is impossible to unplug or disconnect the switch box structure because the cross-head j by engaging the undercut socket y' locks the switch box structure to the insulating disc d as already set forth.

The construction of the switch indicated might be considerably varied and I do not limit myself as to this so long as a detachable switch box structure is used capable of being combined with a split connection box applied to a cable or main in lieu of a lamp a connection structure and interchangeable therefor as herein related.

The Fig. 13 gives a good idea of the uses and possibilities of my invention, as, in this figure I indicate a main cable with split connection box structures applied thereto.

At A is shown a structure with split connection box for attachment to the cable and interchangeable box switch combined there with and an auxiliary cable a connected. On this cable a split boxes and well glass lamps are fitted. Proceeding, I show at B a split cable connecting box capable of receiving either a switch or a lamp. At C I show a further connection to the main cable a with switch box, and an auxiliary cable a. with split connection boxes and bulk-head type of lamps with metal guards.

Further along the diagram, is shown another auxiliary cable at with a sub auxiliary cable a connected therefrom, and so on, the additional showings needing no further description, being obvious, save that where a split connection box is shown with out socketing box for lamp or a box for switch a detachable cover plate marked a is fitted and screwed in place to seal up the box, and shrouds of insulating material are preferably applied to prevent accidental contact being made with the terminals or sockets.

It will be clearly understood that if it be desired to extend the circuit or system by leading out a branch or extension cable from any point, a length of cable with a further number of cable connection boxes could readily be assembled, say in the workshop, in the manner described and provided at one end with one of the aforementioned switches. To connect up the branch or extension circuit to the main' system the switch would be plugged into or applied to the mostconvenient connection box, either by removing a lantern fitting Or a protecting cover in case the particular connection box is scaled up. \Vhere a lantern has bee removed to accommodate a switch from a position where a light is particularlv required It may be replaced by assem ling box on the branch or extension near the switch. Other branch or extension circuits can in like manner be provided to form the complete circuit or network. In order to obviate a long main circuit such as 1s usual in mlnes at present, the malns may be sectionalized or made In lengths and-provided with a suitable num- "her of connectionboxes in each-section and each switch assembled at the commencement of the second and each subsequent length of cable or any of them which would be plugged intothe last connection box of the preceding section. Thus it matter to locate faults in the system by beingable to cut out the various sections.

becomes an easy- The location of faults is also facilitated by the provision of separate fuses for each lighting fitting or lantern whereas the usual present practice is to use only one set of main fuses for the whole-system, A further feature of my invention is that if a lamp in any particular lantern fails, or the fuse becomes blown, that particular lantern may be readily withdrawn and replaced by another complete lantern without interrupting the other lighting on the same circuit. The repair of the faulty lantern could thus be carried out at any convenient time or place as it does not involve interfering with the other lighting on the system and when repaired may be used for replacing any other lantern in the interchangeable system.

Another feature of the system is that it lends itself to being extended at will in any direction from any one of a number of points or connection boxes.

I declare that what I claim is:

1. For electric lighting purposes of the kind specified, a splitconnection box comprising socketing elements adapted to clamp on a cable without cutting same, inlet and outlet apertures, cable glands, an insulating disc,'clam ps for the cores of the cable housed in saidbox, sockets for current conducting V plugs, means to clamp the socketi-ng elements together and an applied cover plate.

2. For electric lighting purposes. a split connection box, comprising socketing elements adapted to clamp on a cable without cutting same, inlet and outlet apertures for the cable, an insulating disc, clamps for the cores of the cable enclosed in the box, sockets for current conducting plugs, means to clamp the socketing elements together, and an interchangeable combining box with spigot and clamping devices, the interchangeable combining box carrying an electric lamp, and means for protecting the lamp.

3. For lighting schemes of the kind indicated, a split connection box consisting of connected elements adapted to. clamp about a cable, entrance and outlet apertures for the cable, an insulated structure secured in the split connection box, cable clamps in said box for the cores of the cable. plug sockets housed in the box, a socket in the lower element of the split connection box, an interchangeable and combining box element, movable fixing means for securing the latter. a spigot on the combining box adapted to fit the socket, and plugs on-the combining box capable of engaging the plug Y sockets.

4. For lighting'schemes of the kind indi-- cated, a split connection-box having combining parts adapted to clamp to a cable, inlet and outlet apertures for said cable, ing means for the cable? an insulating declam vice, cable clamps inside the box for the cores of the cable, sockets in the insulating device, an interchangeable box combining with the split connection box, a machined socket thereon socketing with respect to the split connection box, fastening means for securing the split elments together, an insulating device on the interchangeable box, plugs thereon, a lamp holder, a support for an enclosing glass all whereby interchangeable lighting devices can be applied to a cable without cutting the latter.

5. For lighting schemes of the kind indicated, a split connection box made inparts, and adapted to fit a cable, inlet and outlet for the cable, clamps for the cable, an insulated device in the split connection box, clamps for the cores of the cable therein, sockets, an interchangeable combining box, a spigot and flange thereon, means for fixing a guard for the lamp and whereby the lamp,

is protected and fixed to the interchangeable combining box.

6. For the indicated purposes, an electric light connection box, sockets therein, a detachable lantern structure, a socketing spigot on said structure, plugs in said structure, a machined opening in the connection box, the lantern structure combining with the connection box and producing a confined space and whereby earthing is ensured until complete withdrawal of the plugs as related.

In testimony whereof I have signed my name to this specification.

\ WILFRID BROOKE. 

